svga: add missing switch cases for shadow textures

This doesn't seem to make any difference in testing, but it fixes a
failed assertion when dumping sm3 shaders.

Reviewed-by: Charmaine Lee <charmainel@vmware.com>

src/gallium/drivers/svga/svga_tgsi_decl_sm30.c

@@ -525,6 +525,8 @@ svga_tgsi_sampler_type(const struct svga_shader_emitter *emit, int idx)
    case TGSI_TEXTURE_2D:
    case TGSI_TEXTURE_RECT:
       return SVGA3DSAMP_2D;
+   case TGSI_TEXTURE_SHADOW2D:
+      return SVGA3DSAMP_2D_SHADOW;
    case TGSI_TEXTURE_3D:
       return SVGA3DSAMP_VOLUME;
    case TGSI_TEXTURE_CUBE:

src/gallium/drivers/svga/svgadump/svga_shader_dump.c

@@ -287,6 +287,9 @@ dump_sampleinfo(struct sh_sampleinfo sampleinfo)
    case SVGA3DSAMP_2D:
       _debug_printf( "_2d" );
       break;
+   case SVGA3DSAMP_2D_SHADOW:
+      _debug_printf( "_2dshadow" );
+      break;
    case SVGA3DSAMP_CUBE:
       _debug_printf( "_cube" );
       break;